Various embodiments of particle foam components made of foamed plastic, for example, expanded polystyrene (EPS) or expanded polypropylene (EPP) are known and used in many areas in industry, because they have considerable advantages in terms of weight and insulation, especially in terms of heat insulation. They are frequently used, for example, in the automobile industry to reduce weight compared to metallic components or as insulating components against sound, heat or mechanical stress. However, it is disadvantageous that the aesthetic appearance of the surfaces is not attractive and usually does not meet the requirements of designers. In order to meet these requirements, it is known to provide a particle foam component having a subsequent cover layer made of metal, plastic or material. The cover layer made of metal, plastic or material is either subsequently bonded to the particle foam component or fastened to the particle foam component by means of special holders and in particular clips.
Overspraying a particle foam component subsequently at least in some areas with a plastic material, especially a thermoplastic elastomer, has been known for some time. For this purpose, the particle foam component is inserted into the injection mold, wherein a cavity remains between the particle foam component and the injection mold, and a low-viscosity plastic is injected into the cavity at a high temperature and under high pressure.
The plasticized plastic fills out the cavity between the particle foam component and the wall of the injection mold in the form of a melt. Because of the irregular porous surface structure of the particle foam component, the liquid plastic enters undefined into the near-surface areas of the structure of the particle foam component. In this case, undefined accumulations of material form in the near-surface zones of the structure of the particle foam component and thus non-uniform cross sections of the applied thermoplastic cover layer. This is still acceptable in small particle foam components or in particle foam components, which are invisibly inserted for a user; however, the irregularity over time is conspicuous in large, visible particle foam components and very disturbing in terms of aesthetics.